A geolocation of a radio emitter can be determined using frequency difference of arrival (FDOA) measurements. FDOA measurements can be referred to as differential Doppler measurements. When a signal is received by two receivers separated by a fixed distance, the FDOA is a difference in received frequency of the signal between the two receivers. Multiple observations can result in multiple FDOA measurements, which can be used to estimate the geolocation of the radio emitter. The geolocation of the radio emitter can be estimated using knowledge of the observation points' locations and vector velocities and relative Doppler shifts between pairs of locations as observed by a moving platform (e.g., an aircraft).
Reference will now be made to the exemplary embodiments illustrated, and specific language will be used herein to describe the same. It will nevertheless be understood that no limitation of the scope of the invention is thereby intended.